How To Measure Your Boat Railing

lcarbone1981
Jun 2
2 min read

How to Measure Your Boat Rail the Right Way

If you're looking to mount a flagpole like The Original Swiveler on your boat, getting the right fit is key, and it all starts with measuring your boat’s rail correctly.

Whether you own a center console, pontoon, cruiser, or sailboat, your rail size determines which mount or hardware you’ll need for a secure, long-lasting installation. Here’s a simple guide to help you measure your boat rail like a pro.

🧰 What You’ll Need:

A tape measure or caliper
A notepad or your phone to jot down sizes
Optional: a flexible measuring tape for oddly shaped rails

Step-by-Step: Measuring Your Boat Rail

Step 1: Identify Your Rail Type

Boat rails typically come in two main shapes:

Round tubing (very common on T-tops, bow rails, stern rails)
Square or rectangular rails (more common on pontoon boats)

Knowing the shape will help determine what kind of mount you need.

Step 2: Measure the Outside Diameter (OD)

For round rails, you’ll want the outside diameter of the tubing:

Place your measuring tape or caliper across the thickest part of the rail.
Measure from outside edge to outside edge in a straight line.
Common sizes include ¾", 1", 1¼", and 1½".

💡 Tip: If you're using a caliper, you’ll get the most accurate measurement. Tape measures work too, just be sure to measure as straight across as possible.

Step 3: Measure Width and Height (for square or flat rails)

If your rails are square or rectangular, you’ll need to measure:

Width (side to side)
Height (top to bottom)

This will help when selecting the right clamp-on or bracket-style mount.

Step 4: Check for Clearance

Before mounting anything, make sure there’s enough clear space on the rail:

Avoid areas with bends or joints.
Make sure there's room for tightening brackets or hardware.
Check that nothing (like canvas covers or rod holders) will be in the way.

Why It Matters

Choosing the wrong size can lead to loose mounts, stripped threads, or a flagpole that just won’t stay put. But with accurate measurements, your flagpole will stay secure, with no rattles, no slipping, and no hassle.

Ready to Mount The Original Swiveler?

Once you’ve got your rail measurements, choosing the right mount is easy. If you’re unsure, feel free to contact us with your measurements; we’re always happy to help match you with the perfect setup for your boat.

Fly your flag right, start with the perfect fit.